The present invention relates to an extendable exterior rearview mirror assembly for mounting on a vehicle and, more particularly, to an exterior rearview mirror for mounting on a vehicle which can be selectively extended by the occupant of the vehicle to increase the field of view for example when the vehicle is used for towing a trailer, camper, another vehicle, or the like.
Conventional towing mirrors include a reflective element housed in a frame that is mounted to the body of a vehicle by a support and mounting bracket. The support extends the mirror a greater distance from the body of the vehicle than conventional exterior rearview mirrors in order to provide an unobstructed view to the rear of the towed object. For example, in U.S. Pat. No. 3,119,591 to A. J. Malecki an extendable rearview mirror assembly is disclosed which includes a rigid support for eccentrically mounting the mirror assembly in a fixed extended position from the vehicle. However, these fixed extended rearview mirror assemblies increase the width of the vehicle X in some vehicles, the width is increased beyond the maximum width allowed by conventional vehicle transport trucks which deliver the vehicles to the dealership. Therefore, these extended mirror assemblies are typically installed at the dealership which ultimately increases the cost of the vehicle.
In addition, the fixed extended rearview mirror assemblies is of limited use for a driver who only occasionally tows a trailer. Since such mirror assemblies substantially increase the width of the vehicle, they hamper normal maneuvering through passages such as those defined by garage door openings, drive-through banking structures, and the like. Furthermore, they are more vulnerable to being damaged or to causing damage than conventional exterior rearview mirrors, especially when used by an inexperienced driver. This inconvenience is compounded by the fact that not only do these extended rearview mirrors generally detract from the appearance of the vehicle, they increase the cost of the vehicle.
In response to the needs of drivers who only occasionally tow objects, several extendable mirror assemblies have been developed. For example, in U.S. Pat. Nos. 5,513,048 and 5,489,080 extendable mirrors are disclosed which includes telescoping tubular members which are fixed in position by threaded fasteners. Though simple in construction, these telescoping members typically require the operator to use a tool to adjust the position of the mirror. Moreover, they tend to increase the vibration of the mirror assembly, which may in turn loosen the connection between the telescoping members of the mirror assembly especially when the mirror assembly is in the outboard position.
In U.S. Pat. No. 5,546,239 to Lewis, an extendable mirror element is disclosed in which the mirror element is extended from the mirror casing to an outboard position. Again the mounting bracketry lacks the structure to perform well in vibration. Consequently, the mirror element is more vulnerable to damage.
More recently, manually extendable rearview mirror assemblies have included one or more mounting arms which releasably engage the housing of the mirror subassembly to permit manual extension of the mirror subassembly along the mounting arms, such as disclosed in pending U.S. patent application Ser. No. 08/838,877, filed Apr. 19, 1997, by Peter J. Whitehead, now U.S. Pat. No. 5,969,890, which is assigned to Donnelly Corporation of Holland, Mich., which is herein incorporated by reference in its entirety. Other more recent extendable mirrors include one or more mounting arms which frictionally engage the mirror subassembly housing to permit selective manual adjustment of the position of the housing along the mounting arm, such as disclosed in pending U.S. patent application Ser. No. 08/821,458 filed Mar. 21, 1997, to Steven G. Hoek, now U.S. Pat. No. 5,903,402, which is assigned to Donnelly Corporation of Holland, Mich. and which is herein incorporated by reference in its entirety.
In contrast, U.S. Pat. No. 5,572,376 to Pace discloses an electrically actuated extendable vehicle mirror which includes a rack and pinion system and a drive motor to translate the mirror longitudinally along the mirror support arm. Despite the enhanced control of the position of the mirror, the Pace assembly does not include any safety features that prevent the mirror from being damaged when it inadvertently overextended or provide a manual override option which are both highly desirable. In addition, the Pace drive assembly is relatively complicated and the associated parts increase the weight of the mirror assembly significantly. With an increased number of parts, the cost of manufacture increases. Further, weight increases of this magnitude tend to increase the vibration of the mirror assembly and degrade the performance of the mirror.
Consequently, there is a need for an extendable exterior rearview mirror that can be installed at the factory, which provides extended field of view required when towing vehicles and yet be retracted to a normal operating position where it does not hamper the maneuverability of the vehicle. Moreover, the extendable rearview mirror should have minimal impact on the vibration of the mirror assembly and be relatively easy to adjust between non-towing and towing positions by the occupant of the vehicle without the need for tools and yet provides a safety mechanism and manual override option.
Accordingly, the present invention provides an improved extendable exterior rearview mirror assembly, especially suited for towing vehicles, which is selectively adjustable between a retracted position for normal non-towing use and one or more extended positions in which the mirror assembly is outboard of its normal position allowing an increased field of view to the rear of a towed trailer or the like. These functions are provided by a drive assembly which allows the occupant of the vehicle to selectively adjust the position of the mirror housing and a clutch mechanism which provides a safety release for the drive assembly and, further, allows manual adjustment of the mirror housing.
According to one aspect of the invention, an extendable exterior rearview mirror assembly includes a mounting bracket adapted for mounting to a vehicle, a support supported by the mounting bracket, a mirror subassembly having a housing and a reflective element supported by the housing and being movably mounted on the support, and a drive assembly supported in the housing. The drive assembly selectively engages the support to move the housing with respect to the support to adjust the position of the mirror subassembly. The extendable exterior rearview mirror further includes a clutch for decoupling the driver from engagement with the support which provides a safety mechanism and a manual override option. In one form, the mirror subassembly is selectively moved along the support between inboard and outboard positions by the drive assembly.
In another form, the support comprises a pair of support arms, with the support arms extending into the housing of the mirror subassembly. The support arms are interconnected by a member with the member being coupled to the drive assembly. In one form, the member is releasably coupled to the drive assembly.
According to another form, the drive assembly includes a motor, a drive pulley, an idler pulley, and a belt which extends around the drive pulley and the idler pulley. The belt is coupled to the support such that when the motor drives the drive pulley, the housing moves along the support. The support may comprise a pair of arms, with the support arms being interconnected by a member and with the member being coupled to the belt.
In yet another form, the drive assembly includes a motor and a plurality of rollers. The motor drives the rollers to frictionally engage the support to move the housing along the support. For example, the driver may include a drive rod, with the rollers being mounted on the drive rod with both the drive rod and the rollers extending into the support. The support may comprise a tubular member, with the rollers engaging the inner surface of the tubular member to thereby move the housing along the support.
According to yet another form of the invention, the drive assembly includes a lead screw and a motor. The lead screw extends through a portion of the support and is driven by the motor to move the housing on the support. Preferably the support includes a pair of support arms, with the support arms being interconnected by a member. The lead screw extends through the member. Optionally, the member includes flexible thread engaging portions for engaging the lead screw whereby the flexible thread engaging portions disengage from the lead screw when a force is applied to the housing in the direction of the extension thus permitting manual adjustment of the housing along the support.
In another form, the support includes a tooth rack. The drive assembly includes a motor and at least one movable piston which is driven by the motor to drivingly engage the tooth rack to selectively move the housing along the support. In one form, the piston is mounted on a shaft, which is driven by the motor. The shaft imparts motion to the piston and moves the piston in a cycloidal path to drivingly engage the tooth rack. Optionally, the drive assembly may include a plurality of piston members and a corresponding plurality of drivers, with the drivers selectively and sequentially moving the pistons into engagement with the tooth rack to move the housing along the support. For example, the drivers may comprise solenoids.
According to another aspect of the invention, an extendable exterior rearview mirror assembly includes a mirror subassembly having a housing and a reflective element, a bracket which is adapted for mounting to a vehicle, a support which is mounted to the bracket, and a link which pivotally mounts the mirror subassembly to a the support. The mirror assembly further includes a drive assembly supporting the housing which is drivingly coupled to the support and moves the housing between a retracted position and at least one extended position which define a direction of extension. The drive assembly includes a clutch for decoupling the drive assembly from the support when a force is applied to the housing in the direction of extension to provide manual adjustment of the position of the housing.
As will be understood, the extendable exterior rearview mirror assembly of the present invention provides numerous advantages over the prior known mirror assemblies. The extendable exterior rearview mirror assembly provides an extended field of view for towing vehicles and yet can be retracted to a normal operating position by the occupant of the vehicle to return the vehicle to its normal width. Therefore, the extendable exterior rearview mirror assembly of the present invention can be installed at the factory. Moreover, the extendable mirror subassembly of the exterior rearview mirror assembly includes a safety release so that the mirror subassembly can be manually adjusted and, further, the drive assembly is protected from damage if the mirror assembly is inadvertently overextended.
These and other objects, advantages, purposes and features of the invention will become more apparent from the study of the following description taken in conjunction with the drawings.